The objective of this research project is to discover the mechanisms by which the activities of the dopa decarboxylase (DDC) structural gene, Ddc, and adjacent genes with related functions are regulated during the development of Drosophila melanogaster. The gene coding for DDC is located in the midst of a cluster of functionally related and perhaps coordinately controlled genes. Genetic, developmental, and DNA analysis of the Ddc coding region provide important insights into the structure and organization of the Ddc gene and the adjacent regions. The analysis of sequence-specific DNA-binding proteins involved in Ddc regulation will be essential for the elucidation of those mechanisms which underlie the regulation of the Ddc gene. We propose to isolate and characterize proteins that bind specifically to cloned DNA from the vicinity of the Ddc gene and identify sequences to which they bind. We will determine the diversity and relative abundance of these DNA-binding proteins in tissues where DDC activities appear to be subjected to distinctive developmental and genetic regulation. Furthermore, the developmental profile for these proteins with respect to their tissue- and temporal-specific appearance will be determined.